In a public transport, bus bunching (i.e., clumping, convoying, or platooning) may refer to a group of two or more transit vehicles (such as buses or trains), which were scheduled to be evenly spaced running along the same route, are running instead within the same location at the same time. This occurs when at least one of the vehicles is unable to keep up to its schedule and therefore ends up in the same location with the other one or more other vehicles that are plying the same route. The end result may be unreliable service and longer effective waiting times for some passengers on routes that had nominally shorter scheduled intervals.
Another unfortunate result may be the occurrence of overcrowded vehicles followed closely by near-empty ones. To eliminate or reduce this problem, various solutions have been proposed over the last few decades. In particular, bus routing, bus stop planning, and bus scheduling are some of the typical approaches that have been studied extensively.
In recent years, with the advances in computer science, new technologies have been developed and adopted for handling the bus bunching problem. For example, forecasting of bus bunching could become more accurate when trends can be deduced from historical data. However, empirical evidence has shown that the problem is not well solved yet.